Thanks all. I removed the condensation as best as I could, and used brown paper lunch bags to protect the grafts from scorching heat. The scions still looked fresh to me; I am very happy with the quality of the scions that I received.
I may have an idea why this happened. I put the scions in the fridge right after they were delivered - the FedEx envelop felt warm to me, and after I was done with work, i took the scions out of the fridge and started grafting right away.
Next time I'll either leave the scions out at room temperature and work on them on the same day, or I'll wait a bit longer to graft after taking the scions out of the fridge.